1. Field of the Invention
The present invention relates to a fuel pump module mounted in a fuel tank, which stores fuel, and for mainly supplying the fuel stored in the fuel tank into an internal combustion engine and particularly to a fuel pump module for detecting internal pressure of a fuel tank. The invention also relates to a vehicle tank internal pressure sensor mounted in a vehicle fuel tank for detecting internal pressure of the fuel tank.
2. Description of the Related Art
In a fuel pump module according to a related art, a pressure sensor (tank internal-pressure sensor) is attached to a plate (bracket) fixed to a fuel tank body. When attaching the pressure sensor to the plate, the circumference of a tray fitted to an opening, which is defined in the plate, from a lower surface side of the plate is fixed to the plate by welding or the like. A through-hole is formed in the center of the tray. A nipple of the pressure sensor is thread-engaged with the through-hole from a front surface side of the plate by use of an internal circumferential threaded portion of the through-hole, and attached to the front surface of the plate. Lead wires for sending out pressure detected by the pressure sensor as an electric signal are connected to a signal processor while the lead wires are lumped with lead wires connected to a plurality of terminals mounted on a front surface of the plate and electrically connected to a liquid level detecting unit on a lower surface (e.g., see patent literature 1).
[Patent Literature 1]
JP-A-Hei.4-325316 (page 3 and FIGS. 2 to 5).
In the fuel pump module according to the related art, a space above the plate is occupied by the pressure sensor because the pressure sensor is disposed on the plate, especially sensor elements such as a semiconductor diaphragm and a diaphragm housing portion constituting the pressure sensor are disposed above the plate (opposite to the inside of the fuel tank). A fuel delivery pipe, a return pipe, a breather pipe, a power-supply connector, and so on, may be disposed in the space above the plate. In this condition, the degree of freedom for arrangement of these parts is lowered. In addition, the size of the bracket needs to be reduced in accordance with the requirement for reduction in size of an opening of the fuel tank. For this reason, the degree of freedom for arrangement of other parts than the tank internal-pressure sensor is lowered.
The invention is developed for solving the problems. An object of the invention is to provide a fuel pump module and a vehicle tank internal pressure sensor, which have high degree of freedom for arrangement of parts in a space above a bracket closing an opening of a fuel tank.
According to the invention, there is provided a fuel pump module including a bracket, a fuel pump, and a tank internal-pressure sensor. The bracket closes an opening of a vehicle fuel tank. The fuel pump is held in the bracket and sends out fuel stored in the fuel tank. The tank internal-pressure sensor includes a diaphragm, a housing portion, an external pressure lead-in portion, and a lead-in hole. The diaphragm is disposed in an inside of the fuel tank viewed from a principal surface of the bracket. The diaphragm receives internal pressure and external pressure of the fuel tank. The housing portion houses the diaphragm. The external pressure lead-in portion has smaller section area than the housing portion. The external lead-in portion leads the external pressure of the fuel tank into the tank internal-pressure sensor. The lead-in hole is defined in the bracket and leads one of the external and internal pressures of the fuel tank. The tank internal-pressure sensor detects the internal pressure of the fuel tank on the basis of an output of the diaphragm.
According to the invention, there is provided a fuel pump module including a bracket, a fuel pump, and a tank internal-pressure sensor. The bracket is made of an electrically insulating resin. The bracket closes an opening of a vehicle fuel tank. In the bracket, a conductive terminal is insert-molded, which has one end serving as an external connection end. The fuel pump is held in the bracket and sends out fuel stored in the fuel tank. The tank internal-pressure sensor includes a diaphragm, a power-supply terminal, a signal terminal, and a lead-in hole. The diaphragm receives internal pressure and external pressure of the fuel tank. The lead-in hole is defined in the bracket and leads one of the external and internal pressures of the fuel tank. The power-supply terminal and the signal terminal are connected to the other end of the conductive terminal. The tank internal-pressure sensor detects the internal pressure of the fuel tank on the basis of an output of the diaphragm.
In addition, according to the invention, there is provided a vehicle fuel tank internal pressure sensor including a bracket and a tank internal-pressure sensor. The bracket closes an opening of a vehicle fuel tank. The tank internal-pressure sensor includes a diaphragm, a housing portion, an external pressure lead-in portion, and a lead-in hole. The diaphragm is disposed in an inside of the fuel tank viewed from a principal surface of the bracket. The diaphragm receives internal pressure and external pressure of the fuel tank. The housing portion houses the diaphragm. The external pressure lead-in portion has smaller section area than the housing portion. The external lead-in portion leads the external pressure of the fuel tank into the tank internal-pressure sensor. The lead-in hole is defined in the bracket and leads one of the external and internal pressures of the fuel tank. The tank internal-pressure sensor detects the internal pressure of the fuel tank on the basis of an output of the diaphragm.